Methods and apparatus of spatial relation switching in new radio system

A User Equipment (UE) comprising:

• a receiver that receives a spatial relation configuration to switch to a target spatial relation for an uplink channel in a new radio (NR) network, wherein the spatial relation configuration indicates a spatial filter of the uplink channel is Quasi-Co-Located (QCLed) with one or more spatial filters of one or more downlink reference signals (DL RSs);
• a control circuit that determines whether the target spatial relation is known or unknown based on a list of predefined conditions, wherein the target spatial relation is known when the spatial relation configuration was received within a predefined period of a previous transmission for beam measurement or reporting for the QCLed DL RS of the target spatial relation, the UE has sent at least one measurement report for the QCLed DL RS of the target spatial relation, the target spatial relation remain detectable during a spatial relation switching period, and a signal quality of the QCLed DL RS of the target spatial relation is better than a predefined threshold;
• and
• a beam management handling circuit that switches to the target spatial relation directly when the target spatial relation is known, otherwise performs spatial filter training for a QCLed DL RS when the target spatial relation is unknown.